[R-sig-Geo] Plotting direction vectors from an aspect map

[Greg Snow]

For adding arrows, look at the my.symbols and ms.arrows functions in the TeachingDemos package.

-- 
Gregory (Greg) L. Snow Ph.D.
Statistical Data Center
Intermountain Healthcare
greg.snow at imail.org
801.408.8111


> -----Original Message-----
> From: r-sig-geo-bounces at r-project.org [mailto:r-sig-geo-bounces at r-
> project.org] On Behalf Of Jonathan Greenberg
> Sent: Thursday, September 15, 2011 7:18 PM
> To: r-sig-geo
> Subject: [R-sig-Geo] Plotting direction vectors from an aspect map
> 
> R-sig-geo'ers:
> 
> Given an aspect raster (GDAL-readable), is there a way to plot the
> aspect image using arrows representing each cell's direction?  I'm
> assuming I have to convert the raster to a set of points -- are there
> arrow symbols and, if so, can you rotate them based on some parameter?
> 
> Thanks!
> 
> --j
> 
> --
> Jonathan A. Greenberg, PhD
> Assistant Project Scientist
> Center for Spatial Technologies and Remote Sensing (CSTARS)
> Department of Land, Air and Water Resources
> University of California, Davis
> One Shields Avenue
> Davis, CA 95616
> Phone: 415-763-5476
> AIM: jgrn307, MSN: jgrn307 at hotmail.com, Gchat: jgrn307
> 
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